Pressurizing grow room?

My question is about ventilation, Is it better to have a positive, negative or relatively neutral atmospheric pressure within your grow room/ tent? You can cause a negative pressure by having extra blowers (exhaust), conversely you can have a positive pressure by having more intake than exhaust. OR, is it better to leave the room at a relatively neutral pressure; having equal sizes of exhaust/intake? I don't know and wonder if anyone has experimented????

i've only done negative pressure, works wonders

Negative, for the sole reason that everything is leaves through the scrubber.

I have no intake or exhaust. Perfect room control.

Negative with a less passive intake to still allow fresh air (screened) and negative pressure to throw shit up and out.

Exhaust generally speaking top 1/2 of grow height space.
Intake generally speaking bottom 1/2 of grow height space.

Don't place right next to each other

By "less passive" do you mean forced air like from a blower or will something smaller work just as well. (ex. like a computer fan inside some ducting?)